Thread-controlling mechanism for sewing-machines.



D. S. SEYMOUR.

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES APPLICAHON mu) SEPT. 15, 1916.

1,276,127. Pate11tedAug.2O,19l8.

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ops". SEYMOUR. THREAD cowmoume MECHANISM'FORSEWING MACHINES.

. APPLICATION FILED SEPT-15,1916. 1,276,127.

Patented Aug. 20, 19181 3 SHEETSSHEET 2.

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THREAD comnoume MECHANISM FOR SEWING MACHINES.

' APPLICATION FILED SEPT-1 5. 1916- 1 ,276, 1 27 Patented Aug. 20, 1918.

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UNITED STATES PATENT OFFICE.

DUDLEY S. SEYMOUR, 0F OAK PARK, ILLIN OIS,.AS'SIG-1\TOR T0 UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS. A CORPORATION OF ILLINOIS.

THREAD-CONTROLLING MECHANISM FOR SEWING-MACHINES.

To all "11 710221 it may concern Be it known that I, DUDLEY S. SEYMOUR, a citizen of the United States, residing at Oak Park, in the county of Cook, State of Illinois, have invented certain new and use ful Improvements in Thread-Controlling Mechanism for Sewingddachines, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in thread controlling mechanisms for sewing machines, and more particularly to the thread controlling mechanism for needle threads of a multiple needle stitching mechanism, such, for example, as shown in the patent granted to Russel G. Woodward, April 29, 1890, No, 427,026.

Prior to my invention, as shown in the patentreferred to above, it had been customary to provide a slack thread controlling device which was actuated by the presser foot as the thickness of the material varied so as to vary the slack supplied to the needle in accordance with the thickness of the material being stitched. This slack thread controlling device operated upon. the threads of all the needles.

An object of the present invention is to provide a thread controlling mechanism wherein there is a slack thread controlling device for the thread of each needle which is independently controlled by the thickness of the material adjacent the respective needles.

In the drawings 1- Figure 1 is a front view of a sewing machine having my improvement-s applied thereto, a portion of the cloth plate being broken away to show the looper;

Fig. 2 is an enlarged detail view, partly in front elevation and partly in section, showing the end of the overhanging arm and the thread controlling devices thereon;

Fig. 3 is an enlarged detail, in side elevation, of the end of the overhanging arm and the thread controlling devices;

I ig. l is a plan view of the end of the overhanging arm and the thread Controlling devices attached thereto;

Fig. 5 is a plan view showing a portion of the end of the overhanging arm, the thread controlling levers, and the thread guides carried thereby;

Patented Aug. 20, 193.8.

Application filed-September 15. 1916. Serial No. 120,335.

Fig. 6 is a view, similar to Fig. 2, but showing a slightly modified form of the invention;

Fig. 7 is a view, similar to Fig. 3, but showing this modified form of the invention; and

Fig. 8 is a view,'similar to Fig. 4, but showing the modified form of the invention.

It is well-known that the thickness of the fabrics being stitched often varies considerably and devices have been provided for giving slack to the needle threads which devices are controlled by the presser foot so that, as the thickness of the fabric increases, more slack is given to the needle threads and as the thickness of the fabric decreases, less slack is given thereto. An example of this mechanism is shown in the Woodward patent above referred to. In this patent, there are two needles, and a single controlling device operates upon both of the needle threads.

The present invention consists primarily in providing a separate and independent controlling device for each of the threads of a multlple needle stitching mechanlsm, and

' these controlling devices are separately actuated by the thickness of the material adjacent the respective needles. In one form of the invention the presser foot is divided longitudinally, forming two sections which are mounted so as to yield independently of each other. These sections bear on the fabrics adjacent the respective needles.

will not be raised. As above noted, there is a separate thread controlling device for each needle thread. One of these thread controlling devices is connected with one section of the presser foot, and the other is connected with the other section of the presser foot. Therefore, when the thickness of the fabric increases at one needle and not at the other, additional slack thread will be given to the one needle where the thickness; has increased. It is obvious that this separate control of the needle threads for the respective needles may be accomplished in other ways, the essential feature being that each thread controlling device will be responsive to the thickness of the material adjacent its respective needle.

Referring more in detail to the draw-' l have shown the invention as applied to a sewing machine having a work support 1 which is mounted on a bed plate An overhanging arm is carried by the bed plate, and in the free end of the overhanging arm the needle bar -1 reciprocates. This needle bar is provided with two needles 5 and 6. Cooperating with the needles 5 and 6 beneath the work support is a locper 7 which is mounted on a carrier 8 pivoted to a looper support 9. The looper carrier 8 is oscillated by a link 10 from the needle lever extension 11 of the needle lever The needle bar reciprocated by this needle lever 12 through alink connection 13. Said needle lever is oscillated by an eccentric strap 141 which cooperates with an eccentric on the main shaft 14..

The material to be operated upon is held upon the work support by a presser foot 15. This presser foot is carried by a presser bar 16 which is mounted in the o .'erhanging arm 3. The presser bar is held normally against the work support by a leaf spring 17 and may be raised by a hand lever 18. The presser bar 16 is also connected to a guide bar 19 which reciprocates in suitable lugs 20. These parts are of the usual construction, and further description thereof is not thought necessary.

The presser foot 15 is formed in two sections 21 and The section 21 is rigi with the shank of the presser foot, while the section is yieldingly supported on the shank. v The manner of supporting the yielding section will be described in detail hereinafter. The yielding section is forced toward the work support'by a spring 23. The two sections 21 and 22'are formed by dividing the presser foot longitudinally, and these two sections are so located that the needle 5 passes through the yielding section 22 of the presserfoot, while the needle 6 passes through the rigid section 21,

The thread for the needle 6 is indicated at 12, while the thread for the needle 5 is indicated at 12/. The thread it passes through the tension 24, and thence through a guide eye 25 formed in a wire attached at'26 to a thread controlling lever 27. This thread controlling lever 27 is mounted on a pivot stud 2'8. and is formed with a segmental gear 29. which mesnes with a rack 30 attached to a collar 31, which collar is clamped by a set-screw 32 to the presser bar 16. The needle thread 4?. passes throu h a tension 33. and thence to a guide eye 3% formed in a wire attached at 35 to a thread controlling lever 36, and thence to a thread guide -12 at the upper end of the needle bar. This thread controlling lever is mounted onthe pivot stud 28 and is formed with a segmental rack 37 which meshes with a rack bar 38. The rack bar 38 is rigidly attached to a sleeve 39 which is free to slide on the presser bar 16. An arm 40 is also attached to the sleeve and this arm projects downwardly and is secured to the section of the pre: er foot. The section 22 of the presser foot is provided with a shank 22 which fits within a pocket formed in the shank of the fixed foot section 21. The section 22 has bodily movements in avertical plane only. The lower end of the arm 10 is reduced to form a stem 40 and a resultant shoulder 4.0 This stem [its in a corresponding vertically disposed opening formed in the shank 22, and is fixed thereto by a cross pin 22*. \Vhen the section 22 is up, as shown in the drawings, the shoulder 40 will be disposed at a point above the offset shankof the section 21 so as to allow section to, drop below the section 21. The shoulder 40 also limits the downward movement of the section 22 relative to the section 21 when the presser bar is raised by the operator. The openings in the offset shank at each end of the cross pin 22 are merely for the purpose of inserting or withdrawing said cross pin.

From the above description, it will be apparent that, when the section 21 of the footis raised, the presser bar 16 moving up wardly therewith will lift the rack 30, and this will oscillate the controlling lever 27 so as to move the thread guide 25 down wardly. This downward movement of the thread guide 'ives up slack to the needle, as the position of this thread guide relative to the tension and the thread guide 12 has been changed. In other words, a downward n'iovementof the thread guide 25 brings it nearer to a straight line between the thread guide 12 and the tension 24 and, of course, this gives slack to the needle thread passing through the guide. Both needle threads at and a pass through this guide 12 and then to their respective needles. If the section 22 is not raised at the time the section 21 is 'aised, then the arm 40 remains as before, the presser bar 16 sliding in the sleeve 39 and, therefore, the guide 341 for the needle thread a does not shift and no additional slack is given to this needle thread. It will thus be seen that, if the thickness of the material increases under the section 21 of the foot, while the thick ness of the material under the section 22 remains the same, additional thread will be given, to the needle 6 to accommodate this extra thickness of the fabric, without giving up any additional thread to the needle 5 so that the needle loops of the respective needles will both be drawn tight although the. thickness of the fabric has varied under thread guide 34 moving downwardly to give up slack to the needle 5, while the threadv guide maintains its normal position. a If the fabric varies under-both sections of the presser toot, then both guides will be moved to give slack to the needles. a,

It will be apparent from the above de-l scription that I have provided a thread controlling device for each. needle threadwhich is responsive to the thickness of the fabric being stitched by its respective needle. While I have described the threadcontrolling levers as controlled by a sectional presser foot, it will be understood that theselevers may be otherwise controlled, the essent1al feature being the separate and individual control of the devices by the varying thick nesses of the materials being stitched by the needles. "While I have shown a. single looper cooperating with both needles, it will also be understood that other forms of complemental stitch-forming mechanism may be used as the thread controlling devices regulate particularly the needle loops in the stitches being formed.

In Figs. 5 to '7, inclusive, I have shown a slightly modified form of the invention, the stitch forming mechanism and the presser foot mechanism being precisely the same as above described. The thread controlling lever 27 carrying the thread guide is also controlled in precisely the same way by the rack bar 30 carried by the collar 31 which is secured to the presser bar 16. The thread controlling lever 36 carrying the thread guide 34 is controlled in a slightly dilferent manner. This thread controlling lever 36 is formed with a segmental rack 37 which meshes with a rack bar 43. This rack bar attached. to a sleeve 44 in order to slide freely on the presser bar 16. Said sleeve has a downwardly projecting bar 45 which is pivoted at its lower end on a pin 46 at tached to a lever 47. This lever 47 is fulcrumed at 48 on a bracket 49 which is attached to the lower end of the guide bar 19 for the presser bar 16. The end of the overhanging arm 3 is formed with an opening for the depending arm 45. is forked at its front end to engage between shoulders 50 and 51 formed on the shank 52 carrying the yielding section 22 of the presser foot. The spring 23 bears on the upper end of this shank. As the section 22 is raised, the shank 52 will move upwardly therewith, and this will raise the free end of the lever 47 The lever will move the arm 45, the sleeve 44, and the rack bar 43 upwardly, and this will depress the thread guide 34.

The lever 47 The'operation ot :these parts is precisely the-same as those described above, the only difference being the including of the lever between the arm on the sleeve and the shank of the sectlon 22 01' the, prcsser :loot.

It is obvious that minor changcsgin the details'ojliconstruction and the arrangement of: parts may be made without departing iron: the spirit of this invention, set forth :m the appended-claims.

Having thus described the invention, what is claimed as new is l. 'The combination of a work support, stitch-forming mechanism, said stitch tormting inechanisn'i including a plurality of needles, a slack thread-controlling device toreach needle and a movable fabric-engaging member adjacent each needle, said slack thread controlling device for each needle being connected to the movablefabric-engaging member adjacent its respecl: tive needle.

2. The combination of a work support, a pre 'ser ir'oot, stitch-forming mechanism, said stitch-forming mechanism including a plurality of needles, a slack thread controlling device for each needle, said presser foot having an independently movable section for each needle, and devices for connecting the slack thread controlling device for each needle with the corresponding section of the presser foot. I

3. The combination of a work support, a passer foot cooperating therewith, said presser foot being divided longitudinally to form two independently movable sections, stitch-forming -1nechanism including two spaced needles disposed so as to operate upon the material passing under the respective sections of the presser foot, a thread controlling lever for each needle thread, a thread guide carried by each controlling lever, and devices for connecting one of the thread controlling levers to one of the sections of the presser foot, and independent devices for connecting the other thread controlling lever to the other section oi the presser foot.

4. The combination of a work support, an overhanging arm, a needle bar, two needles carried by said needle bar, a thread guide at the upper end of the needle bar for the needle threads, tension devices on the overhanging arm for the needle threads, a thread-controlling lever pivoted to the overhanging arm for each needle thread, a thread guide carried by each thread controlling lever, the thread guides on the controlling levers being so disposed relative to the tension devices and the guide on the end of the needle bar whereby movements of the levers will either give or take up slack thread in the respective needle threads, and means controlled by the thicknesses of the fabrics being stitched at the respective needles for varying the position of the thread-controlling lovers in accordance with the thicknesses of the materials at said respective needles.

5. The combination of a work support, an overhanging arm, a needle bar, two needles carried by said needle bar, a thread guide at the upper end of the needle bar for the needle threads, tension devices on the overhanging arm for the needle threads, a thread controlling lever pivoted to the overhanging arm for each needle thread, a thread guide carried by each thread controlling lever, the thread guides on the controlling levers being so disposed relative to the tension devices and the guide on the end of the needle bar whereby movements of the levers Will either give or take up slack thread in the respective needle threads, a presser foot, said Presser foot being divided longitudinally to form two separate yielding sections, said sections of the presser foot being so disposed as to be respectively responsive to the thickness of the material operated on by the 1espective needles, devices for connecting one section of the resser foot with the threadcontrolling lever cooperating with the needle thread of the needle operating on the material engaged by said section of the presser foot, and devices for connecting the other Copies of this patent may he obtained for he cents; each, by addressing the commissioner at l 'atents,

Uuhilgton, 1L9. v 

